Kinetic Modeling of Molten Iron Demanaganization with Flux Injection in a Torpedo-shaped Furnace
ZHU Cheng-yi LI Guang-qiang CHEN Zhao-ping XIA Xing-ming HONG Xiao-jie
Key Laboratory of Ferrous Metallurgy and Resources Utilization, Ministry of Education, Wuhan University of Science and Technology Key Laboratory of Ferrous Metallurgy and Resources Utilization, Ministry of Education, Wuhan University of Science and Technology Baoshan Iron & Steel Co. , Ltd. Scientific Research and Development Institution of Baosteel Co., Ltd. Key Laboratory of Ferrous Metallurgy and Resources Utilization, Ministry of Education, Wuhan University of Science and Technology
Abstract： Based on the coupled reaction model, a kinetic model was developed for hot metal demanganization with flux injection in a torpedo-shaped furnace using oxidation slag, considering the effects of penetration ratio and residence time of the injected flux, mixing time of the hot metal bath on demanganization rate, and then the model was validated. The calculated results obtained by simulating the actual process using this model show that when the powder containing 58.5% FeO and basicity controlled at 0.85 carried by oxygen with 10 Nm3/min flow rate is injects into 250 t hot metal at 1623 K and the injection rate controlled at 400 kg/min, silicon content in hot metal decreases to the lowest level after treatment for 2~3 min. Demanganization rate increases gradually only silicon content in hot metal decreases below 0.3%. Manganese content decreases to the value below 0.1% which is the lowest level in the present bath after treatment for 6~7 min, which can meet the requirements of low manganese steel. Desiliconization rate is higher than that of demanaganization under the calculation conditions, and decarburization is observed, while phosphorus content is nearly not changed. The demanganization is enhanced by decreasing the particles size of injected flux to 25 mm, increasing the immersion depth of lance to 1.6 m, increasing powder supply rate to 400 kg/min, increasing FeO content in the flux suitably and decreasing silicon content to a certain level before demanganization when the powder is ensured to contact with hot metal fully as well as avoid agglomerating and blowing out of the bath.
2011, Vol. 11 
